Antigenic Characterization of Cell-Cultivated Astrovirus Serotypes and Development of Astrovirus-Specific Monoclonal Antibodies

Abstract

Cultivation of human astroviruses in human embryonic kidney or LLCMK2 cell cultures was corroborated for four of the five serotypes originally reported (types 1, 2, 4, and 5). By using type-specific rabbit antisera and immunofluorescence of virus-infected cells, we readily distinguished between serotypes of astrovirus; however, these serotypes showed a high degree of cross-reactivity by enzyme-linked immunoassay, a result indicating the presence of a group antigen. We prepared monoclonal antibodies to astrovirus type 2 antigen and selected them on the basis of group antigen reactivity. The antibodies were reactive with the four astrovirus serotypes that we could cultivate, as well as with the Marin County strain of astrovirus. A previously reported cell-cultivated astrovirus type 3 also reacted with the monoclonal antibodies. These monoclonal antibodies, and the finding of group reactivity among the human astroviruses, should facilitate studies on the importance of these viruses as agents of viral gastroenteritis.

Identification of astrovirus serotypes from children treated at the Hospitals for Sick Children, London 1981–93

“…The use of EM in other countries showed that astrovirus infection occurs in children throughout the world [9]. The production of a group specific monoclonal antibody in 1988 [10] in combination with polyclonal antisera raised in Oxford to five strains of astrovirus enabled the development of an enzyme immunoassay as an alternative to EM for screening faecal samples [11]. The application of this assay has recently enabled larger epidemiological studies to be carried out on samples from developing countries, e.g.…”

Adaptive Immunity Restricts Replication of Novel Murine Astroviruses

“…The turkey model of avastrovirus pathogenesis has been used to characterize astrovirus disease and immune response (32,33) but lacks the ability to easily dissect host determinants of astrovirus infection and immunology. Furthermore, while mamastrovirus tissue culture systems do exist (23,38), the ability to elu-cidate molecular mechanisms that control mamastrovirus infection and pathogenesis has been hampered by a lack of a small-animal model.…”

Identification of Human Astrovirus Genome-Linked Protein (VPg) Essential for Virus Infectivity

“…After being washed, cells were blocked for 1 h at room temperature in 20 mM glycine-PBS containing 10% FBS. Cells were incubated overnight at 4°C with a 1:10,000 dilution of the monoclonal antibody (MAb) 8E7 (kindly provided by P. Sanders at RBiopharm AG), which recognizes astroviral structural proteins (23). An indocarbocyanine 3-conjugated anti-mouse antibody was used as the secondary antibody at a 1:5,000 dilution.…”